From: Dave Jones <davej@redhat.com>
Date: Fri, 22 Sep 2006 23:15:23 +0000 (-0400)
Subject: [CPUFREQ] Fix some more CPU hotplug locking.
X-Git-Tag: v2.6.19-rc1~1283^2~1
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ddad65df0048e210c93640b59b3bad12701febb6;p=linux-2.6

[CPUFREQ] Fix some more CPU hotplug locking.

Lukewarm IQ detected in hotplug locking
BUG: warning at kernel/cpu.c:38/lock_cpu_hotplug()
[<b0134a42>] lock_cpu_hotplug+0x42/0x65
[<b02f8af1>] cpufreq_update_policy+0x25/0xad
[<b0358756>] kprobe_flush_task+0x18/0x40
[<b0355aab>] schedule+0x63f/0x68b
[<b01377c2>] __link_module+0x0/0x1f
[<b0119e7d>] __cond_resched+0x16/0x34
[<b03560bf>] cond_resched+0x26/0x31
[<b0355b0e>] wait_for_completion+0x17/0xb1
[<f965c547>] cpufreq_stat_cpu_callback+0x13/0x20 [cpufreq_stats]
[<f9670074>] cpufreq_stats_init+0x74/0x8b [cpufreq_stats]
[<b0137872>] sys_init_module+0x91/0x174
[<b0102c81>] sysenter_past_esp+0x56/0x79

As there are other places that call cpufreq_update_policy without
the hotplug lock, it seems better to keep the hotplug locking
at the lower level for the time being until this is revamped.

Signed-off-by: Dave Jones <davej@redhat.com>
---

diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 25eee53942..c2ecc599dc 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -350,12 +350,10 @@ __init cpufreq_stats_init(void)
 	}
 
 	register_hotcpu_notifier(&cpufreq_stat_cpu_notifier);
-	lock_cpu_hotplug();
 	for_each_online_cpu(cpu) {
 		cpufreq_stat_cpu_callback(&cpufreq_stat_cpu_notifier, CPU_ONLINE,
 			(void *)(long)cpu);
 	}
-	unlock_cpu_hotplug();
 	return 0;
 }
 static void